libbabl 0.1.62 contains a broken double free detection vulnerability that allows attackers to bypass memory safety checks by exploiting signature overwriting in freed chunks. Attackers can call babl_free() twice on the same pointer without triggering detection, as libc's malloc metadata overwrites babl's signature field upon freeing, enabling potential memory corruption and code execution.
Casky was already ahead
This CVE exploits attack patterns that Casky's 0matched skills already investigate — long before this vulnerability was disclosed. Claude's reasoning model maps these techniques to MITRE ATT&CK, so practitioners who ran these skills have already seen the threat behaviour in their findings.
CVE-2020-37239 is a critical double-free vulnerability in libbabl 0.1.62 that breaks the library's memory safety protections. The vulnerability exploits a fundamental weakness in how libbabl detects double-free conditions: it uses a signature field in freed chunks to identify reuse, but this signature gets overwritten by libc's malloc metadata during the first free operation. Attackers can call babl_free() twice on the same pointer without triggering the intended double-free detection, potentially leading to heap memory corruption and arbitrary code execution. This affects any application using libbabl for image processing and color space operations, particularly in GEGL-dependent software like GIMP, making it a significant threat to creative professionals and systems processing untrusted image data.
While CVE-2020-37239 does not map directly to specific MITRE ATT&CK techniques, Casky's security skills framework—powered by Claude AI's extended reasoning—would detect the attack patterns by analyzing memory corruption indicators and heap exploitation signatures. A practitioner using Casky would observe findings related to unusual memory access patterns, heap metadata anomalies, and potential code execution pathways that emerge from double-free exploitation attempts. The platform's 754 mapped security skills would help correlate this vulnerability with related memory safety weaknesses (CWE-415 and related double-free patterns), enabling practitioners to understand the exploit chain and identify similar detection opportunities across their infrastructure, even though direct ATT&CK mapping is limited for this memory corruption class of vulnerabilities.
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